chemically produced synthetic stimulant that mimics meth. >> it's an analog of methalone which is a scheduled controlled substance. so this can be treated as a scheduled controlled substance. >> and it came from the country that according to the d.e.a. is manufacturing and shipping most of the synthetic drugs worldwide. >> from china. mainland china. >> it's no secret to law enforcement where it comes from. and it's no secret to drug dealers seeking to become entrepreneurs in the new world of designer drugs. >> any laboratory in china, if you send them what's called a cast number, which is -- it's just a number that's designated to essentially every chemical substance that exists, as long as it's not scheduled they will manufacture it for you specifically. it's called a custom synthesis. and ship it to you. >> charles carlton, who sold the drugs that killed elijah stai